A Faraday cage is a shield formed by conducting material such as metal to protect the enclosure from external electromagnetic radiations. When an external electrical field is present, the Faraday cage prevents the electric field from penetrating within the cage. If the cage is grounded, the excess charge will flow to ground instead of residing on its outer surface. Traditionally Faraday cages are made of copper, aluminum foil or other metals.
Typically, the effectiveness of the Faraday cage in prevent electromagnetic radiation from passing through is dictated by the conductivity of the cage material and the thickness of the metal. Because Faraday cages are typically made of metal, and/or a metal mesh incorporated within a matrix, they are bulky and difficult to move around. Furthermore, it is not practical to implement a traditional Faraday cage on a ship to shield the whole ship and its antennas due to size and weight constraints. Additionally, a Faraday cage will prevent the passage of electromagnetic radiation through the cage in both directions, both inbound and outbound. Although there are times when a vessel may want to protect itself from inbound electromagnetic radiation, there is also a need for a vessel to selectively emit radio waves, radar emissions, etc. in the conduct of its daily operations. Thus, it is also desirable to have a Faraday cage which can be selectively activated and deactivated.
In view of the above, it is an object of the present invention to provide a Faraday cage and method for deployment, which uses seawater to provide the shielding effect. Another object of the present invention is to provide a Faraday cage and method for deployment that is extremely lightweight relative to the amount of area/volume it is designed to protect. Still another object of the present invention is to provide a Faraday cage and method for deployment that can be selectively activated and deactivated. Another object of the present invention is to provide a Faraday cage and method for deployment where the size and corresponding area of coverage can be adjusted during operation of the Faraday cage. Yet another object of the present invention is to provide a Faraday cage whose protective properties can be adjusted according to the level of electromagnetic radiation desired by the user. Another object of the present invention is to provide a Faraday cage and method for deployment that is easy to use in a cost-efficient manner.